: I'm still confused. : : When I submit an ad proof to a client it send it 4x5 at 75 dpi and it : zips out. that's because you are using photoshop and setting it to resize the image inadvertantly - Photoshop is unique in it's method of using dpi.. it's origin is to blame. lets say the original scan was at 300 dpi - you have an image that is 300x5 inches=1500 pixels by whatever When you set the dpi to 300 in PS without unticking the resample option, you are effectively saying to photoshop 'use the oldest upsizing algorithm in the book and multiply your image x times' - it'll still look the same size in Photoshop, but to every *other* program in the world it is now HUGE! try it - and look at the image information, to see just how many additional pixels PS put in! All junk too I might add.. I just whacked in am image that was 500 pixels wide, set it to 300 'dpi' with resample checked and it blew out to 2000+ pixels wide - effectively turning a 1Mb file into an 18Mb file (eeek!) I saw this a lot at college when students inadvertantly resized their images to 2400 dpi to send to the epson printer 'casue that's what it printed at' (utter rubbish) - they'd effectively turn an image that was a meg or so in size to something in the order of gigabytes and the printer would take HOURS to process the information before it could eliminate the junk and print the image! : What's going on to make this happen if they are the same size and dpi : doesn't matter? dpi is utterly irrelevant and photoshop should have dispensed with it in version 2. Because they persisted, people the world over have remain confused - and worse, because *other* programs didn't have it and because people demanded this redundant oddity, the other guys added it thus perpetuating the unnecessary confusion :( : : PS. Perhaps we're talking about PPI vs. DPI but I'd still like to : have this clarified so I understand it clearly. Thank you. PPI is a print term, while dpi is effectively something that should have remained in the domain of machine language - it's how many squirts of ink (dots , NOT pixels) the printer squirts out per inch. nothing more, nothing less. some printers gob out 300 squirts, they are 300 dpi printers and largely they may be good for graphics but they are awful for photos. laser printers these days run around 600 dpi and they make very fine lined images, look great but can't reproduce the best colours (if you are printing at 300 ppi, there is only so much a 600 DPI printer can do with two squirts of ink per pixel to make the colours look accurate) the photo printers run around 4800 DPI for say the Canons - that's a whole SIXTEEN squirts of ink per pixel (at 300 ppi) to make a colour - VERY nice looking! :) this help any? Karl
